Pain, tingling, or numbness in the calves, thighs, and/or buttocks brought on by physical activity is called intermittent claudication (IC). IC is the primary symptom of peripheral arterial disease (PAD) that occurs because blockages in the lower extremity arteries hinder blood flow to the legs. Current conservative treatment for patients with PAD consists of supervised treadmill walking exercise (STW). After STW, patients with PAD exhibit improvement in maximum walking distances(1), but little is known regarding gait biomechanics. This study was conducted to determine the effectiveness of the current conservative treatment on gait biomechanics and lower extremity strength in patients with PAD.
Fifteen patients (total of 26 claudicating limbs; age: 66±1.9 years, height: 1.75±2.24 m, weight: 89.23± 5.01 kg), diagnosed with PAD were recruited from the Omaha Veterans’ Affairs Medical Center. Patients visited the lab prior to and after completing a prescribed 12-week, 3 times/week STW. Five over-ground walking trials for each leg were performed while kinematics (60 Hz; Motion Analysis Corp., USA) and kinetics (600 Hz; Kistler Instruments, USA) were recorded pre and post 12-weeks STW. Absolute claudication distance (max walk distance) was determined through a progressive, graded treadmill protocol (2 miles/hour, 0% grade with 2% increase every 2 minutes) until maximal claudication pain. Inverse dynamics was used to calculate peak joint torques and powers for the ankle, knee, and hip (Visual 3D, C-Motion, Inc., USA). Peak plantar flexor strength was assessed using an isokinetic dynamometer (Biodex Medical Systems, USA). Differences pre to post STW were determined using paired t-tests (α=0.05).
In agreement with the previous literature, absolute claudication distance significantly increased post STW. No significant differences between baseline and post STW were detected for joint torques and powers, or lower extremity strength. Supervised treadmill walking appears to address a cardiovascular mechanism in PAD. STW may only be helping to improve stamina. The lack of any functional training may be reinforcing poor mechanics, which will continue to hinder patient function with a poor chance for long term benefits to be realized. Future investigation should include functional exercises in patients with PAD.
Listed In: Biomechanics